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CN-122018331-A - Six-degree-of-freedom sliding mode control method and medium for fixed-wing unmanned aerial vehicle based on full-drive modeling

CN122018331ACN 122018331 ACN122018331 ACN 122018331ACN-122018331-A

Abstract

The invention belongs to the technical field of flight control and intelligent robust control of aircrafts, and particularly relates to a six-degree-of-freedom sliding mode control method and medium of a fixed-wing unmanned aerial vehicle based on full-drive modeling. The method comprises the steps of constructing a full-drive control input vector according to translational channel control quantity (comprising equivalent thrust in each axial direction of an inertial system obtained by comprehensive thrust decomposition of the unmanned aerial vehicle) and rotation channel control quantity (comprising steering surface deflection angles of ailerons, elevators and rudders of the unmanned aerial vehicle), constructing a six-degree-of-freedom state vector according to position and posture states of the unmanned aerial vehicle under the inertial system (comprising the translational quantity and rotation quantity of the unmanned aerial vehicle in each axial direction of the inertial system), constructing an affine full-drive model according to the full-drive control input vector, the six-degree-of-freedom state vector and an input gain matrix, and realizing six-channel unified modeling and decoupling regulation and control so as to improve track tracking precision, robustness and energy consumption inhibition level.

Inventors

  • WANG YAN
  • GE QUANBO

Assignees

  • 南京信息工程大学

Dates

Publication Date
20260512
Application Date
20260410

Claims (10)

  1. 1. The six-degree-of-freedom sliding mode control method for the fixed-wing unmanned aerial vehicle based on full-drive modeling is characterized by comprising the following steps of: determining an action gain matrix of a rotation channel control quantity on translational acceleration of the unmanned aerial vehicle in each axial direction of an inertial system according to a pneumatic model of the unmanned aerial vehicle under the inertial system and a coordinate transfer matrix from the inertial system to the inertial system, wherein the rotation channel control quantity comprises ailerons, elevators and rudder deflection angles of the unmanned aerial vehicle; Constructing a full-drive control input vector according to the translational channel control quantity and the rotational channel control quantity, wherein the translational channel control quantity comprises equivalent thrust in each axial direction of an inertial system, which is obtained by decomposing comprehensive thrust of the unmanned aerial vehicle; Constructing an input gain matrix between a full-drive control input vector and the six-degree-of-freedom state vector based on the action gain matrix; Constructing an affine type full-driving model according to the full-driving control input vector, the six-degree-of-freedom state vector and the input gain matrix; Constructing a position posture tracking error according to the expected state of the position posture state, and constructing a sliding mode surface according to the position posture tracking error; constructing a full-drive control structure of a full-drive control input vector based on the affine full-drive model and the sliding mode surface; and solving the translational channel control quantity and the rotational channel control quantity based on the full-drive control structure so as to realize unmanned aerial vehicle control.
  2. 2. The six-degree-of-freedom sliding mode control method of the fixed wing unmanned aerial vehicle based on full-drive modeling according to claim 1, wherein the expression of the affine full-drive model is as follows: ; Wherein, the The state of the position and posture is represented, Representing a six degree of freedom state vector; Representing a drift term; Representing an input gain matrix; Representing a full drive control input vector; Representing a comprehensive disturbance term; 、 And Respectively representing the translational motion of the unmanned aerial vehicle in the x axis, the y axis and the z axis under the inertial system; 、 、 Respectively representing translational acceleration of the unmanned aerial vehicle on an x axis, a y axis and a z axis under an inertial system; 、 And Respectively representing the rotation quantity of the unmanned aerial vehicle around an x axis, a y axis and a z axis under an inertial system; 、 、 Respectively represent 、 And Is used for solving the second order derivative of the (a), And Respectively represent And First order derivative of (2); 、 、 Respectively representing deterministic components related to the unmanned plane translational momentum in the inertial frame x-axis, y-axis and z-axis; And A first x-axis rudder coupling gain and a second x-axis rudder coupling gain respectively representing the rotation amount of the unmanned aerial vehicle around the x-axis under the inertial system, 、 And The first y-axis rudder-effective coupling gain, the second y-axis rudder-effective coupling gain and the third y-axis rudder-effective coupling gain respectively represent the rotation quantity of the unmanned aerial vehicle around the y-axis under the inertial system; And A first z-axis rudder coupling gain and a second z-axis rudder coupling gain which respectively represent the rotation amount of the unmanned aerial vehicle around the z-axis under the inertial system; representing the quality of the unmanned aerial vehicle; 、 And Linear contribution vectors respectively representing ailerons, elevators and rudders of the unmanned aerial vehicle; The dynamic pressure of air is indicated, Representing a reference area; coordinate transfer matrix representing transformation from body system to inertial system Is the first of (2) A row vector; 、 And Respectively representing equivalent thrust on an X axis, a y axis and a z axis of an inertial system obtained by comprehensive thrust decomposition of the unmanned aerial vehicle; 、 And Respectively representing the control surface deflection angles of an aileron, an elevator and a rudder of the unmanned aerial vehicle; 、 、 disturbance terms respectively representing the planar momentum of the unmanned aerial vehicle in the x-axis, the y-axis and the z-axis of the inertial system, 、 、 Disturbance terms respectively representing rotation amounts of the unmanned aerial vehicle on an x axis, a y axis and a z axis of the inertial system.
  3. 3. The six-degree-of-freedom sliding mode control method of the fixed-wing unmanned aerial vehicle based on the full-drive modeling according to claim 2, wherein, 、 、 Constructed translational drift term The expression of (2) is: ; ; ; Wherein, the Representing translational state vectors A corresponding translational drift term; Representing air density; representing airspeed; representing the quality of the unmanned aerial vehicle; 、 And An x-axis reference aerodynamic coefficient, a y-axis reference aerodynamic coefficient, and a z-axis reference aerodynamic coefficient obtained by mapping an uncontrollable aerodynamic portion representing aerodynamic coefficients of lift, drag, and lateral force, respectively, to the body system; 、 And An uncontrollable aerodynamic portion of aerodynamic coefficients representing lift, drag and lateral forces, respectively; Representing the angle of attack; 、 And Respectively represent the rolling angle speed of the unmanned aerial vehicle under the machine system Pitch angle rate And yaw rate Dimensionless values of (2); 、 And Basic coefficients respectively representing lift force, resistance force and lateral force; And Respectively represent the attack angles The corresponding lift aerodynamic coefficient and drag aerodynamic coefficient; Indicating sideslip angle Corresponding lateral force pneumatic coefficients; And Respectively represent pitch angle rate The corresponding lift aerodynamic coefficient and drag aerodynamic coefficient; Indicating roll angle speed Corresponding lateral force pneumatic coefficients; Representing yaw rate Corresponding lateral force aerodynamic coefficients.
  4. 4. The six-degree-of-freedom sliding mode control method of the fixed wing unmanned aerial vehicle based on the full-drive modeling according to claim 2, wherein the expression of the linear contribution vectors of the ailerons, the elevators and the rudders of the unmanned aerial vehicle is as follows: ; Wherein, the Representing the angle of attack; Representing the deflection angle of the control surface of the aileron Corresponding lateral force pneumatic coefficients; And Respectively represent the deflection angles of the control surfaces of the elevators The corresponding lift aerodynamic coefficient and drag aerodynamic coefficient; indicating the deflection angle of the steering surface Corresponding lateral force aerodynamic coefficients.
  5. 5. The six-degree-of-freedom sliding mode control method of the fixed wing unmanned aerial vehicle based on full-drive modeling according to claim 3, wherein the expression of the sliding mode surface is: ; ; Wherein, the Indicating the surface of the sliding die and the surface of the sliding die, Representing the position and orientation tracking error, A derivative representing a position and orientation tracking error; Represent the first An exponential type adaptive gain is provided, Represent the first Derivative of the individual exponential adaptive gains; The sign function is represented by a sign function, And Representing a first nonlinear correction order and a second nonlinear correction order, respectively; A power exponent representing an adaptation law; Represent the first A gain lower bound for the exponential adaptive gain; Represent the first A fall-back factor for the exponential adaptive gain, Represent the first The growth rate coefficient of the exponential adaptive gain.
  6. 6. The six-degree-of-freedom sliding mode control method of the fixed-wing unmanned aerial vehicle based on full-drive modeling according to claim 5, wherein the expression of the full-drive control structure is as follows: ; Wherein, the Representing the position and posture state Second order derivative of the desired state of (2); an inverse matrix representing the input gain matrix; represents the boundary layer thickness; Representation of Adaptive robust gain over time; Representing a hyperbolic tangent function.
  7. 7. The six-degree-of-freedom sliding mode control method of the fixed-wing unmanned aerial vehicle based on full-drive modeling according to claim 6, wherein the adaptive robust gain is Is the derivative of (2) The expression of (2) is: ; Wherein, the Representing a sliding mode threshold; Representing a reference gain; 、 And Respectively representing a first coefficient, a second coefficient and a third coefficient, 、 And Are all greater than 0.
  8. 8. The six-degree-of-freedom sliding mode control method of the fixed wing unmanned aerial vehicle based on full-drive modeling according to claim 6, wherein the solving of the translational channel control quantity and the rotational channel control quantity adopts a modularized decoupling solving mode, and the solving step comprises the following steps: Control input vector to be fully driven Is decomposed into translational control input vectors composed of translational channel control amounts And a rotation control input vector composed of rotation channel control amounts ; Will input gain matrix Recorded in the form of blocks , 、 And Respectively representing a first sub-gain matrix, a second sub-gain matrix and a third sub-gain matrix, wherein the second sub-gain matrix The control quantity of the rotation channel is an action gain matrix of translational acceleration of the unmanned aerial vehicle in each axial direction of an inertial system; decomposing the affine type all-drive model into a translation model and a rotation model, wherein the expression of the translation model and the rotation model is as follows: ; Wherein, the Is a translational state vector which is used for the translation, In order to rotate the state vector of the state, And Second order derivatives respectively representing the translational state vector and the rotational state vector; And The drift items corresponding to the translational state vector and the rotational state vector are respectively adopted, And The comprehensive disturbance items respectively correspond to the translational state vector and the rotational state vector; Translational control input vector And a rotation control input vector The solution result of (2) is expressed as: ; ; Wherein, the Representing translational state vectors A second derivative of the desired state of (c), Representing rotational state vectors Second order derivative of the desired state of (2); the rotation control input vector representing the last moment, An inverse matrix representing the first sub-gain matrix; an inverse matrix representing a third sub-gain matrix; Representing the sliding surface of the flat subsystem, Representing a rotor subsystem slip plane; The expression of the sliding mode surface of the flat subsystem is: Wherein, the Representing the translational position tracking error, A derivative quantity for representing a translational position tracking error; And Respectively representing a first translational nonlinear correction order and a second translational nonlinear correction order; representing a sign function; a diagonal gain matrix representing a translational three-channel low power error term, 、 And Respectively representing a first x-axis translational gain, a first y-axis translational gain and a first z-axis translational gain; A diagonal gain matrix representing a translational three-channel high power error term, 、 And Respectively representing a second x-axis translational gain, a second y-axis translational gain and a second z-axis translational gain; the expression of the sliding mode surface of the rotor subsystem is as follows: Wherein, the Indicating the rotational attitude tracking error, A derivative quantity representing a rotational attitude tracking error; And The first rotational nonlinear correction order and the second rotational nonlinear correction order are represented respectively, A diagonal gain matrix for a rotated three-channel low power error term, wherein, 、 And Respectively representing a first x-axis angular gain, a first y-axis angular gain, and a first z-axis angular gain; to rotate the diagonal gain matrix of the three-channel high power error term, 、 And Respectively representing a second x-axis angular gain, a second y-axis angular gain, and a second z-axis angular gain; representing a sign function.
  9. 9. The six-degree-of-freedom sliding mode control method of the fixed-wing unmanned aerial vehicle based on full-drive modeling according to claim 6, wherein the comprehensive disturbance term of the affine full-drive model is observed through an enhanced disturbance observer, and the expression of the enhanced disturbance observer is as follows: ; ; ; ; ; ; Wherein, the The time of day is indicated as such, Representing enhanced disturbance observer output for approximating a synthetic disturbance term Is used as a disturbance compensation term of the (c), And (3) with Respectively representing a first adaptive tuning gain and a second adaptive tuning gain of the enhanced disturbance observer; representing observed sliding mode variables; representing the base gain of the enhanced disturbance observer; And Respectively representing a disturbance change rate normalization amount and a disturbance energy density normalization amount; Representing a supercoiled auxiliary state; A derivative quantity representing the supercoiled auxiliary state; representing positive coefficients; representing the fundamental gain of the enhanced disturbance observer, The comprehensive index of the disturbance structure response is represented, Representing the structural response gain factor, Represents the coefficient of the co-scale coupling relation, Representing a switching function; representing states corresponding to position and attitude Is defined as the generalized pose state vector of (a), The derivative of the generalized pose state vector is represented, Representing a generalized velocity state vector of the vehicle, Representing the integrated control input vector(s), A derivative representing a generalized velocity state vector, As an auxiliary variable, a control signal is provided, A derivative representing the auxiliary variable; After a disturbance compensation term output by the enhanced disturbance observer is introduced into the full-drive control structure, the expression of the full-drive control structure is adjusted as follows: 。
  10. 10. A computer readable storage medium, characterized in that the storage medium stores a computer program for executing the six-degree-of-freedom sliding mode control method of the full-drive modeling-based fixed wing unmanned aerial vehicle according to any one of claims 1 to 9.

Description

Six-degree-of-freedom sliding mode control method and medium for fixed-wing unmanned aerial vehicle based on full-drive modeling Technical Field The invention belongs to the technical field of flight control and intelligent robust control of aircrafts, and particularly relates to a six-degree-of-freedom sliding mode control method and medium of a fixed-wing unmanned aerial vehicle based on full-drive modeling. Background In recent years, the fixed wing unmanned aerial vehicle is widely applied to tasks such as low-altitude economy, emergency rescue, large-scale inspection and the like by virtue of the advantages of high cruising speed, long range, high energy efficiency and the like. However, the dynamics of the fixed wing aircraft naturally presents an underactuated structure, the number of actual control inputs is less than the degree of freedom of a system, so that strong nonlinear coupling and channel constraint exist between translation and attitude, and when large maneuver, fault, saturation constraint or complex disturbance scenes are executed, linkage effects of coupling enhancement, controllable margin reduction and extruded robust margin easily occur, and the closed loop precision and stability margin are obviously restricted. From a modeling perspective, existing research usually explicitly reflects aerodynamic effects in the form of lift, drag, lateral force and its moment coefficients, angle of attack, sideslip angle dynamics, and aerodynamic derivatives, but "taking aerodynamic" is not equivalent to "full drive modeling". Under the traditional underdrive input structure, even if the model contains a more complete pneumatic item, the thrust and the control surface still act on the system through a limited physical channel, and the input and output driving matrix of the model still can be rank deficient or irreversible in structure, so that the full-freedom unified decoupling regulation and control and isomorphic design are difficult to realize. The aerodynamic force and moment generally meet the scaling relation related to the square of speed, so that the equivalent input gain from the control surface deflection angle and the thrust to the acceleration is changed with the square of speed, the same control surface deflection angle is amplified by dynamic pressure in a high-speed section, is obviously attenuated in a low-speed section and is further modulated by an attack angle and a sideslip angle, the aerodynamic effect of the control surface appears in a moment form in a rotation equation, and can be projected into a translation channel through a translation equation, so that the cross-channel coupling enhancement and the input mapping condition number degradation are represented, and the saturation and speed and bandwidth limitation of an actuator make the strong time-varying gain difficult to cover by simply increasing the control force, the structural amplification of the control surface deflection angle and the equivalent input gain from the thrust to the acceleration are easy to cause oscillation and energy waste in the high-speed section, and the low-speed section is easier to trigger saturation and hysteresis, so that the response is delayed and even decoupled and degraded. Therefore, the prior art needs a six-degree-of-freedom sliding mode control method of the unmanned aerial vehicle which is isomorphically matched with the full-drive model. Disclosure of Invention Aiming at the problems existing in the prior art, the invention aims to provide a six-degree-of-freedom sliding mode control method and medium based on a full-drive modeling fixed-wing unmanned aerial vehicle, which are used for constructing a full-drive control input vector according to translational channel control quantity (comprising equivalent thrust in each axial direction of an inertial system obtained by comprehensive thrust decomposition of the unmanned aerial vehicle) and rotation channel control quantity (comprising ailerons, elevators and rudder deflection angles of the rudders of the unmanned aerial vehicle), constructing a six-degree-of-freedom state vector according to the position and posture state of the unmanned aerial vehicle under the inertial system (comprising the translational quantity and rotation quantity of the unmanned aerial vehicle in each axial direction of the inertial system), and constructing an affine full-drive model according to the full-drive control input vector, the six-degree-of-freedom state vector and an input gain matrix, so that six-channel unified modeling and unified decoupling regulation are realized, and track tracking precision, robustness and energy consumption inhibition level are improved. In a first aspect, the invention provides a six-degree-of-freedom sliding mode control method of a fixed-wing unmanned aerial vehicle based on full-drive modeling, which comprises the following steps: determining an action gain matrix of a rotation channel control quantity on translation